Scrap metal preheater



July 2, 1968 J. J, CIOCHETTO 3,390,872

SCRAP METAL PREHEATER Filed May 31, 1966 INVENTOR. J05EPH .1 C/dCl/ETTU Stat s PetmiQ x J 3,390,872 1 w z: 1' 1. SCRAP METAL PREHEATER' Joseph J. Ciochetto, Allison Park, Pa., assignor to 1 Kprp r Ce tra a orpq io D l a Filed May 31, 1966, Ser. No. 553,930 ,2 Claims. (Cl. 266 -27).

I T his invention relatesto steel'making and, more particularly, to improve" apparatulsdor preheating scrap metal an'd'other additives used in'rnaking steel. j

[accordance with the invention, the apparatus for preheating scrap material includes a pair of "coplanar tubular charging legs 'pivotally connected together and disposed in end 'abuttingrelation. The internalsurfaces of the tubular charging legs are refractory lined to protect and insulate the steel leg structure from heat generated in each leg. toraise the temperature of the scrap metal; The lower portion of each tubular charging leg is fitted with spaced apart outer cylindrical surfaces that surround the lower portion of the tubular charging leg in a spaced relation and form passages of a labyrinth for the exitof hot gases of combustion after they have passed through scrap metal in the unit and raised the tempe'rajture of the scrap metal. Each charging leg is provided with a fixed saddle supportthatis adapted toengage and coact with a'pair of fixed supports, adjacent a discharge area, in such a mannerthat when the preheater unit is disposed between the. fixed supports and is lowered'relative to the supports, the saddles engage the supports and the charging legs pivot relative to the fixed supports and to each other to open the preheater unit and discharge the preheated scrap metal h e om 'For[a .further understanding of the present invention for advantages and features thereof, reference may be made to the following description taken in conjunction with the accompaying drawing which'shows, for the purpose of exemplification, a preferred embodiment 'of the invention. i

In the drawing: v v i FIG. 1 is a schematic elevational view, partly in section, of a" preferred embodiment of the invention in one op a ep s t FIG. 2 is a sectional view,' at an enlarged scale, of a portion of the preheater of FIG. 1; i 1 FIG. 3 is' a schematic view ofthe preheater of FIG. 1 in another'operative position; and' a FIG. 4 is 'a sectional view along line of FIG. 1. Referring to FIG. 1, the scrap preheater 11 of the invention includes a, pair of right hand 13 and left hand 15 tubular charging legs of generally circular cross-section that are disposed in substantially eoplanar, converging end abutting relation. The upper end of each charging leg 13, 15 isintegrally formed to anelbow portion 17, 19-respectively, and both charging legs 13, 15 and elbow portions 17, 19 a'r'e fashioned preferably from steel plate, such asis indicated at 21. I

As shown in FIG. 1, the lower half portion of the shell plate 21 of each charging leg 13, 15 terminates along a radial line 23. Surrounding the shell plate 21 in this area and in spaced relation thereto, inner and outer 3,390,872 Patented July 2, 1968 31 overlies the shell plate 21, but is shaped so as not cylinder shell portions 25, 27 are welded to the shell plate 21 and are themselves maintained inspaced apart relation by suitable spacer pieces 29 (FIG. 2).

' Adjacent the upper portion of each charging leg 13, 15, and in the vicinity of the elbow 17, 19, a girth plate to overlie the outer cylindrical plate 27 and is welded to the outer surface of the shell 21. However, between the upper end of outer plate 27 and the elbow 17, 19, the girth plate 31 entirely surrounds the shell plate 21. The girth plate 31 supports upwardly'projecting juxtaposed arms 33, 35 that are pivotally connected together by a pivot pin 37. Preferably, a washer 39 or other suitable member is disposed around the pivot pin 37 and between opposed surfaces of the juxtaposed arms 33, 35 to maintain them in spaced apart relation.

The arms 33, 35 are also pivotally connected, as at 41, 43, to a pair of links 45, 47 that are themselves pivot ally connected together, as at 49. The pivot pin 49 also serves as a connection to alifting device, such as a powered crane hook 51.

Adjacent the upper edge of the girth plate 31, a saddle support structure 53 comprised of a horizontal rectangularbody portion 55 and a triangular bracket portion 57 is welded, preferably, to each shell plate 21 at a location opposite a plane passing through the pivot pins 37, 49, or about where shown in FIG. 1. The rectangular body portion 55 has in the lower surface a groove 59 that has, preferably, the cross sectional form and shape shown in FIG. 1 for a purpose'that will be described hereinafter.

. The operation of the preheater apparatus 11 may be understood readily by describing a typical cycle of operational steps. It may be assumed that the preheater unit 11 has just discharged a load of preheated scrap metal and isreadyfor reloading. The unit 11 has been returned to a scrap loading station and is supported on a transfer car 61 (FIG. 1), or other suitable mobile apparatus. The transfer car 61, shown schematically in FIG. 1, has an open center type body portion 63, comprised of interconnected side and end rails respectively, that is supported on conventional railroad type trucks 65. At each end of the transfer car there are cradle supports 67, 69 that are preferably pivoted at 71, 73 to suitable mountings on the transfer car.

In the embodiment of the invention shown in FIG. 1, the preheater unit 11 has been place-d in the cradle supports 67, 69, and the upper half of the lower ends of the charging legs 13, 15 are in the closed end abutting position; the edges of the respective legs 13, 15 abutting along a line 75 that lies in a plane passing through the pivot pins .37, 49. It will be noted that the juxtaposed edges of the inner and outer spaced apart cylindrical plates 25, 27 do not abut, but are spaced apart so as to form a slightly divergent gap 77 at the bottom of the preheater unit 11.

It will be understood that, at the scrap metal loading station, the upper ends of the elbows 17, 19 are open and are not closed. Scrap material may be loaded into the charging legs 13, 15, using conventional equipment such as electro-rnagnets, grab buckets, or the like apparatus. Scrap-material will tend to gravitate toward the bottom of the unit 11 because of the sloping charging legs 13, 15, and such scrap will not tend to bridge or become wedged in the charging legs. Preferably, the inner surface of the shell 21, both surfaces of the shell 25, and the inner surface of the shell 27 are lined with suitable refractory material 79 that serves to protect and insulate the steel plate from the heat generated within the charging legs to raise the temperature of the scrap metal placed therein.

The scrap metal should, preferably, be loaded no higher than the level suggested at 81 in FIG."1;- that is to say, there should be a space 83 or volume within each leg 13, 15, between the top level 81 of the scrap and the top of the elbow 17, 19. The space 83 is necessary to accommodate the flame generated by a burner 84 in a removable cover, such as the cover 85, that may be placed over the elbow 17, 19 at heating station.

As soon as the unit 11 is loaded with scrap material, the transfer car 61 and the unit 11 may then be moved in any suitable manner to a heating station. At the heating station, the unit 11 will be picked up by the powered crane hook 51 and set upon a suitable support structure that is preferably fixed in place at the heating station, and that is provided with suitable exhaust ducts located beneath the unit to exhaust the hot gases after they have permeated the scrap metal in the unit and emerged from the gap 77. After placing the unit 11 on the fixed heating station support structure, the covers 85, each having therein a fuel burner 84, are placed over the upper ends of the elbows 17, 19 and the joint therebetween is sealed in any suitable manner such as, for example, by a sand seal or a refractory lute type seal. Thereafter, the burners may be fired with any suitable fuel and the scrap metal heated by the hot gases of combustion.

The hot gases generated by the burning fuel are prevented from escaping at the covers because of the luting seal and so the gases are urged to permeate down through the scrap metal and exhaust from the unit at the gap 77. Some of the hot gases, however, exit the charging legs 13, 15 through the passages of a labyrinth formed between the spaced apart shells 25, 27. These gases flow generally in the direction of the arrows A as shown in FIG. 2. As mentioned herein, suitable exhaust ducts (not shown) are provided at the heating station to remove the emerging hot gases from the environment and also to urge the gases to permeate the scrap metal in the unit 11.

After the scrap metal has attained a desired mean temperature, in the range of say about 1550 E, the burners 84 may be shut off and the covers 85 removed. Thereupon, the powered crane hook 51 may be used to pick up the unit 11 by engaging the pivot pin 49 and transporting the unit to the furnace area.

Referring to FIG. 3, two fixed spaced apart support bars 87, 89 are provided adjacent a discharge area, such discharge area being above a conventional type of furnace opening 91. It will be understood that the furnace opening 91 may be in either an open hearth furnace, an electric arc furnace, or a basic oxygen furnace or other type of furnace. The horizontal distance between the support bars 87, 89 is about equal to the distance between the outer edges of the groove 59 in the saddle supports 53. Also, the supports 87, 89 are located above the furnace 91 a convenient distance for purpose to be presently explained.

As the powered crane hook 51 lowers the preheater unit 11 between the support bars 87, 89, the link mechanism, that supports the preheater unit 11 and that connects to the arms 33, 35, maintains the charging legs 13, 15 in the closed or edge abutting condition. But, after the saddle supports 53 contact the support bars 87, 89, a further lowering of the unit causes the unit 11 to slide on the fixed support bars 87, 89 until the bars engage the curved inner wall of the groove 59. Further lowering of the unit causes the charging legs 13, 15 to pivot relative to themselves about the pivot pins 37, and also relative to each other about the fixed support bars 87, 89. Under these circumstances, the charging legs 13, 15 move to the open position (FIG. 3) and the preheated scrap material 93 discharges from the preheater unit into the furnace opening 91.

As soon as the scrap metal 93 has discharged from the unit 11, the unit may then be raised by elevating the powered crane hook 51, and the charging legs 13, 15 will 4 pivot again to the closed end abutting relation after the unit 11 has been raised above the level of the fixed support bars 87, 89. Thereafter, the empty preheater unit 11 may be returned to the transfer car 61, which remained at the heating station, and then both the transfer car and heating unit may be moved to the scrap loading station from which they started initially.

A feature of the present invention is that the sloped arrangemnet of the charging legs 13, 15 prevents a bridging or a wedging of the scrap bundles within the unit 11. Scrap metal that is loaded into the top end of each charging leg 13, 15 gravitates naturally toward the bottom zone of theunit, but cannot force open the legs 13, 15 of the unit because of the linkage arrangement connected to the arms 33, 35. Further, the unit is supported'in the cradle structure 67, 69, and the unit cannot-be forced open for this reason also.

Another feature of the invention is that the scrap material may be of conventional size and shape (medium or heavy scrap in some cases), and it is not necessary that a cushion load of light scrap be loaded into 'theb'ottom of the unit first as is done in other conventional scrap preheater units. A feature of the invention is that the hot gases generated by the burners are forced downwardly through the scrap load and thence outwardly to the exhaust ducts mentioned hereinbefore. The gases must permeate practically all of the scrap loaded into each charging leg.

Although the invention has been described herein with a certain degree of particularity, it is understood that the present disclosure has been made only as an example, and that various modifications and changes may be made within the scope of the invention as defined by the appended claims.

What is claimed is:

1. Apparatus for use in preheating scrap metal comprising:

(a) first and second cylindrical tubular members;

(b) arms mounted to and extending from said first and second tubular members, said arms being pivotally connected together at a first point intermediate their length;

(c) links pivotally connected together at a second point and pivotally connected to each arm at third and fourth pivot points, said second point pivot being adapted to be engaged by a lifting mechanism whereby when a lifting force is applied to said second point pivot, said first and second tubular members pivot into end abutting relation along a plane passing through said first and second pivot points;

(d) refractory means applied to the inner surface of each said tubular member;

(e) refractory lined spaced apart .third and fourth cylindrical members surrounding the lower portion of each said first and second tubular members in spaced relation thereto, said third and fourth spaced apart cylindrical members defining ducts of a labyrinth passage for hot gases of combustion generated in the end portion of each said first and second tubular member remote from said abutting plane;

(f) saddle supporting means mounted to each first and second tubular member at a level below said first point pivot and on the side of each tubular member opposite said plane of abutment whereby, when said apparatus is suspended from said second pivot point and is disposed between fixed supports engaging said saddle supports, and said apparatus is lowered relative to said fixed supports, said first and second tubular members pivot relative to each other about said first. pivot and each tubular member pivots relative to a respective engaging fixed support, said first and second tubular members pivot in opposite directions and scrap material in said apparatus is discharged therefrom.

5 6 2. The invention of claim 1 wherein: 3,180,724 4/ 1965 Brooke 266-5 (a) saic l first and second cyiindrical tubular members 3,336,020 8/1967 Palsak 266-24 are disposed m a substantially coplanar relatlon. FOREIGN PATENTS References Cited 5 622,757 12/ 1935 Germany. UNITED STATES PATENTS SPENCER O ERHOLSER, P E 559,384 5/1896 Hunt 2944/0 J V 3,128,891 4/1964 Schwenge] 294 9 R. D. BALDWIN, Asszstant Examzner. 

1. APPARATUS FOR USE IN PREHEATING SCRAP METAL COMPRISING: (A) FIRST AND SECOND CYLINDRICAL TUBULAR MAEMBERS; (B) ARMS MOUNTED TO AND EXTENDING FROM SAID FIRST AND SECOND TUBULAR MEMBERS, SAID ARMS BEING PIVOTALLY CONNECTED TOGETHER AT A FIRST POINT INTERMEDIATE THEIR LENGTH; (C) LINKS PIVOTALLY CONNECTED TOGETHER AT A SECOND POINT AND PIVOTALLY CONNECTED TO EACH ARM AT THIRD AND FOURTH PIVOT POINTS, AND SECOND POINT PIVOT BEING ADAPTED TO BE ENGAGED BY LIFTING MECHANISM WHEREBY WHEN A LIFTING FORCE IS APPLIED TO SAID SECOND POINT PIVOT, SAID FIRST AND SECOND TUBULAR MEMBERS PIVOT INTO END ABUTTING RELATION ALONG A PLANE PASSING THROUGH SAID FIRST AND SECOND PIVOT POINTS; (D) REFRACTORY MEANS APPLIED TO THE INNER SURFACE OF EACH SAID TUBULAR MEMBER; (E) REFRACTORY LINED SPACED APART THIRD AND FOURTH CYLINDRICAL MEMBERS SURROUNDING THE LOWER PORTION OF EACH SAID FIRST AND SECOND TUBULAR MEMBERS IN SPACED RELATION THERETO, SAID THIRD AND FOURTH SPACED APART CYLINDRICAL MEMBERS DEFINING DUCTS OF A LABYRINTH PASSAGE FOR HOT GASES OF COMBUSTION GENERATED IN THE END PORTION OF EACH SAID FIRST AND SECOND TUBULAR MEMBER REMOTE FROM SAID ABUTTING PLANE; (F) SADDLE SUPPORTING MEANS MOUNTED TO EACH FIRST AND SECOND TUBULAR MEMBER AT A LEVEL BELOW SAID FIRST POINT PIVOT AND ON THE SIDE OF EACH TUBULAR MEMBER OPPOSITE SAID PLANE OF ABUTMENT WHEREBY, WHEN SAID APPARATUS IS SUSPENDED FROM SAID SECOND PIVOT POINT AND IS DISPOSED BETWEEN FIXED SUPPORTS ENGAGING SAID SADDLE SUPPORTS, AND SAID APPARATUS IS LOWERED RELATIVE TO SAID FIXED SUPPORTS, TO SAID FIRST AND SECOND TUBULAR MEMBERS PIVOT RELATIVE TO EACH OTHER ABOUT SAID FIRST PIVOT AND EACH TUBULAR MEMBER PIVOTS RELATIVE TO A RESPECTIVE ENGAGING FIXED SUPPORTING, SAID FIRST AND SECOND TUBULAR MEMBERS PIVOT IN OPPOSITE DIRECTIONS AND SCRAP MATEIAL IN SAID APPARATUS IS DISCHARGED THEREFROM. 